Testing if a matrix is null in v9.3

[xtc283x]

I've read that for SAS v12.1, there is a new null matrix operator, {}.  The challenge is that I am running SAS v9.3M1. So, in this earlier version, is there a way to test whether or not a matrix is null in v9.3M1?

[Rick_SAS · Accepted solution]

This article provides several ways to test for empty matrices in 9.3: "How to create and detect an empty matrix"

My favorite is

if type(X) = 'U' then...